Method of recording and reproducing sounds or signals.



No. 66l,6l9. Patented Nov. I3, |900. V. PULSEN.

METHOD 0F RECHDINGAND REPHDUClNG SOUNDS 0B SlGNALS. `(Applicmnm med July s, 1899. No model.) a shets-sheet m@ fwd/MQ Patented Nov. ls, |900.A

V. POULSEN. METHOD 0F RECORDING AND REPRODUCING SOUNDS DR SIGNALS.

(Application fled July 8, 1899.;

3 Sheets-Sheet 2 (No Model.)

No. 66I,6|9. Patented Nov. I3, |900. V. POULSEN.

METHOD OF RECORDING AND REPRODUCING SOUNDS OR SIGN'ALS.

(Application led July 8, 1899.) (No Model.) 3 Sheets-Sheet 3.

1 *30 exciting paramagnetic bodies.

of 'this problem is based on the discovery that vALnnlMAR PoULs'nN', o-`r PATENT OFFICE.

coPnNnAenN, DENMARI{.

METHOD Oi' RECORDINQ AND REPRODUCING SOUNDS OR SIGN/ils.

sPncImcArrIolv forming part Letters Patent No. 661.619. dated November 1s, 1900.

' Application and July 8.1899. simi no. 729.198. imipenem.)

To (1155 l0/tom it may concern:4

Be it known that l', VALDEMAR PoULsENa su bjectof the Ki ngof Den mark, residing atCopenhngen, in the Kingdom of Denmark, have '5 invented certain new and useful Improvements` in Methods of and Apparatus for Effearing the Storing np of Speech or Signals by Maguctically Influencing Magnetizable Bodies, (for which I have applied for patents ro in England, No. 8,961, dated April 28, 1899;

in Germany, dated Decemberi), 1898; in Austria, dated April 22, 1899; in IIungary, No. 56,494,dated May 1,1899; in France, 190,276,184,

da'ted April 26, 189i); in Belgium, No. 111,719, i5 dated April 26, 1899; in italy, dated f'lVIay'2,y

1899; in 'Spain,dated April 26, 1899; in Portugal, dated May 8, 1899; in Switzerland, No. 21,005,dated April 25, 1899; in Russia,dated April 26, 1899; in Norway, No. 11,076, dated 2o .April 26, 1899; in Sweden, dat'ed March 20, 1899, and inDenrnark, No. 1,260, dated December 1, 1898,) of which the following is a specification.

It has long been possible to transmit 'mes-- sages, signals, &c., by electrical means. t The present invention represents avery es` sential advance in this branch of science, as

it provides for receiving and temporarily storing messages and the like by magnetically The solution a paramagnectic body, such as a steel wire forA ribbon, which is moved past an electro- 1 magnet connected with an electric or mag- 35 neti'c transmitter, such asa telephone, is magnetically excited along its length in exact correspondence with the signals, messages, or speech, delivered to the transmitter, and', further, that when the magnetically-excited wire 4o is again moved past the electromagnet it will reprod uce'the said signals, messages,or`speech in a telephone-receiver connected with the said electromagnet.

The invention is4 of great importancefor 45 telephonie purposes, as by providinga suit1 able apparatus in combination `vith a telephone communications can be received by the 'apparatus when the `subscriber is absent,

. whereas upon his return he can cause the 5c communications to be repeated by the apparatus.

Further. the oresentinvenfion will replace the. phonographs hitherto "used and provide simpler and better-acting apparat-us.

As is well known, in the usual phonographs cipal reasons why the phonograph has not come more extensively. into use.

this invention is illustrated.

2is a section on lineiazw of Fig. l looking up. Fig. 3 is a section on line y y of Fig. 1 Alooking down, tromagnet and its carrier. on line 4 4 of Fig. 5.

Fig. 4 is a section representation of electrical connections designed for the purpose of explaining the mode of operation of the invention.

Upon this casingis su pported a stirrup-shaped `,frame b, the two arms of`which are arranged on opposite sides of a central spindle c. this spindle is mounted a cylinder d, which spindle in any suitable way, and thespindle itself is fixed to the casing. s

-e is a bow-shaped framecousisting ofa piece of tubing bent into shape and having its ends connected by an arm e', mounted'to turn on 1a hearing at the middle of the frame hby means of ashort stud 44, which passes through "the bow and enters the fraiieb. Rotary motion is imparted to the bow by means of the with awheel 1-3, engaging with a pinion 12 on the hub of'the ar'm e', A fixed ringl 48, car` the vibrations of air transmitted to a memto disturbing noises; which apart from the expense offsuch apparatus is o'neof the p'rin- In the accompanying drawings oneform of' 4Figure 1 is a front elevation and partial'. section of the phonographic apparatus. Fig.-

Fig. 3' isa detail viewof the elec' Fig. 5 is a section on line 5 5 of Fig. 4. Fig. 6 is a diagrammatic In the apparatus illustrated the paramag` of the wheels of which is indicated by a2 is held stationary by being fastened to theA the spindle c.l .The upperend of the bow has clockwork in the casing a, which'is provided rying two annular electrical contacts 49 on Aits upper, su rface is arranged immediately below the arm e', and said arm is provided with a spring-mounted-pin 23, adapted tobe forced into connection with both of said electrical contacts for the purpose of electrically connecting them together. l

Upon the surface of the cylinder d is wound a steel wire g in a uniform helix. the arms of .thebow e is placed a sleevef, adapted to slide freely up and ldown on the bow, it being held in a fixed relation thereto by means of a tongue-and-groove connection or in any othersuitable manner.A This sleeve has pivoted to it a magnet-holder h, the poles of the magnet therein 'being indicated by z'. The magnet-,holder is provided with a' tailpieee k, which is normally pressed upon by a spring Z, tending to force the poles of the magnet out of contact with the wire g.

.p represents a weight adjustably fixed on an-arm 0, pivoted to the sleevef. The arm o is connected with the tail c by a spring m. Centrifugal force acting upon the weight p tends to throw the magnet-holder toward the cylinder d, and thus bring the-poles of the magnet into contact with the wire g, in lwhich operation the spring Z is compressed, so that 'when the centrifugal force ceases said spring will act upon the tailpiece kA to remove the poles of the magnet from the wire g. The arm 'o has two extensionso' and o2, which serve as stops to limit the movement of the weight p in both directions. The sleeve is also provided with a fingere, the purpose of which will be explained hereinafter. With reference to the magnet 't' it may be stated that it may have one or two of its pcie-pieces arranged to engage the wire g. If a single pole-piece is used, the end thereof will be rounded or made wedge-shaped to tit between two adjacent convolutions of the wire and in con-tact with beth of them, while if the two pole-pieces are used, as is shown in the drawings, they may make contact with opposite sides of a single convolution of the wire, the poles being pointed for this purpose, or they may slide in the adjacent grooves between the wires and straddling one convolution.

The two wires r fr, in whichthe magnet i is connected, lead from the magnet through the fopen slot in the bow e, thence u pwardth rough said hollow bow to a point near the upper end thereof, where they pass out through a fiaring nozzle e2, thence around the outside of a drum 17, through a hole in the side thereof, and thence upward toa pair of binding-screws q q, arranged on the opposite sides of the bow e at its' middle point, the wires being slack between said binding-screws and the opening in the drum. From said binding-screws the wires lead on, respectively, to two insulated rings s and t on the'short stud 44'. Upon each of these rings a contact-spring lu, attached to a block v', rests, and to these springs the main wires are respectively connectedby means of the binding-screwsq'. The said drum v17 is On one of- .magnet t instead o mounted freelylon the`upper end of the spindie c, and on its under side it has pivoted to it two weighted levers 18, each of which carries a spring forming a brake-shoe resting to the drum by a conical nut 47, engaging with the hub 46 and with the bow by a similar nut 45, engaging with the end of the stud 44. ,It will now be seen that when the bow e -rotates it. will carry the drum 17 with it.; but

owing to the action of the brake 18 and the wings 16 there will be a certain amount of lagging on the part of the drum which will be permitted by the twisting of the wires 15.

The clockwork is normally prevented from rotating by the weight of the armature 11,.

which acts upon the brake, as shown in Fig. 1. The brake is released bythe electromagnet l0 in a circuit with battery E and a cutout 14, attached to the frame b.

The apparatus so far described is a phonograph, the operation of which may be now referred to.

Let it be assumed that speech or sign-als are being electrically transmitted over the'circuit containing the magnet t", that the sleeve fis at the lower end of the bow, and that thermachine is started by closing the circuit net l0. to rotate around the cylinder d. When the speed is snicient, centrifugal' force acting upon the weight p will cause the core of they magnet t' to be thrown intocontact with the .wire g, whereupon the sleeve will be caused to slide upward upon the bow owing to the spiral arrangement of the wire on the cylinder. At the same time the nndulations of current in the circuit of magnet i will vary the magnet.-

ism of said magnet,`which variations will bev successively imparted to the wire g. The message may continue until the sleeve. j

' reaches the elevation of thecut-out 14, whereupon the finger o3 on the sleeve strikes said cut-out and opens the circuit of magnet 10. Armature 11 then falls'and stops the clockwork, whereupon springl withdraws the poles of the magnet from wire g and the sleeve falls by gravity to its lower position. brake 18 is adjustable, so that the lagging of the-drum 17 behind the bow e willbe just sufficient to wind the wires r'r' upon the drum as the slack in said wires is created by the upward movement of the sleeve f. 'lo reproduce the message which has thusv been The bow e immediately commencesl The ICO

of mag- IIO magnetically recorded, it is only necessary to put a receiving-tele hone into circuit with phone and then start the machine again,

the transmitting telewhereupon the sleeve will travel up on the bow and the poles of the magnet will traverse the Wire g, the successively-varying magnetic condition of which' will react upon the core of the magnet and cause the same undulations of` current to be sent over the line to the receiving-telephone as were previously sent over ,the line to the magnet from the transmittitig-telephone.

The connection of the apparatus to a telephone is shown ip Fig. 6. vided having four terminals 38, 39, 42, .and 43. 'lhese terminals can be connected with each other in three different ways' by means of the switch-lever. In the position shown in the drawings the two terminals 38 and 39- phonograph, and the transmitting-telephone belonging to the same station ,can then be used. To clearly explain this, the course of the current should be followed when the terminals 38 and 42 are connected. When the subscriber turns the crank-handle ot his induction apparatus,a current will pass through the outer coil of the induction-coils R. The current issues from the telephone and passes overv the conductor'36 to the outer coil of the vmagnet 22 is thus excited'and the armature upon the pin 23, begins t-o rise and the connection between the contacts 49 is broken. 'lhe contact 23 consequently exists only for an instant, so that the circuit of the conductors 20 21 -22 23 24 25 is open during the' operation ofthe clockwork and apparatus. Now during the rise of the sleevefand while the electromagnet t', Fig. 3,- is in contact with the Aswitch 19 is prosteel Wire g in the mannervdescribed the subscribercan speak into his transmitter and the spirally wound steel wire g will be correspondingly magnetically excited. 'lliecou rse of the currentin this case is as follows: lt passes from the telephone apparat us through the conductor 36, the outer coil of the induction-coils R, the terminals 42 38, and conductor 37 back to the transmitter. responrlenee with the`matt-erspoken into the transmitter current-s are induced in the inner induction-coil. Such currents issue from thc terminals' 2O 2l, pass through the electromag- `net t', conductor o', terminals 32 33, contact- In exact eorsprings 60 34, and terminals 24 25 back to the innerinduction-coil. 'lhe contact. between 6() and 34 is also eii'eeted by the falling of block 41. The electromagnet t is magnetized in correspondence with the. matter spoken and ytransfers its magnetism tothe steel wire y. The matter thus fixed can now be transmitted over the line by using the third connectionthat is, by connecting the terminals 42 and 43 ofthe switch 19.

If, for example, the message, The subscriber is not at home at present, but will -return at four oclock, at which time please ring again, is fixed to the steel wire and a subscriber at some otherst'ation calls the former, when the contact-pieces 42 43 are connected together the following circuit will be described: The induced current from the transmitting-station will rst pass over t-he conductor 35 to the outer coil of the inductioncoils R and then through the terminals 42 43, whereupon it will pass through these to the line 40, because the terminal 43 is connected with the terminal 39. The line-current willV accordingly not pass through the telephone of the receiving-station, but because the contact 23Y is then closed the electromagnet 22 is again excited by the current generated in the inner coil of the inductioncoils R and the drum d is rotated. The electromagnet 't' will slide along the fixed wire g and gradually rise with the sleevefand will be magnetized in accordance with the speech fixed on the wire. The currents induced thereby pass from the electromagnet t, Fig. 7, through the terminals 33, contact-springs 60 and 34, terminals 24 25 to the inner coil of the induction-coils R, and then through the terminals 20 and 21 t0 the electromagnett'. In

the inner coil of the induction-coils R a cur- Fig. 1, the terminals 30 and 33,`Fig. 7, are

lowing connection is made: .passes from battery E through the terminals` connected with `6l and 62, whereupon the fol- 81 and 32 to the electromagnet fi, through the terminals 21 20, inner`coil of the inductioncoils R, termina-125, contact-springs 34 60,con tacts 33 62 61 BO, contact-spring 29, contacts 2514, and electromagnet 10 back to the battery E. The electromagnet is in this position of the switch uniformly magnetized by the battery E and demagnetizes thereby the steel wire g on the bow e rotating.

For telegraphic purposes the invention can also be used with advantage. It is insuch ease only necessary to receive the current impulses transmitted over the line in the electromagnet while it is in contact with the param'aguetic body. The paramagnetic body may be moved past the electrornagnet, or vice versm Having described .my invention, I claiml l. The method of recording and reproducing,Jr speech or signals which consists in impressing upon an electric circuit containing an electromagnet, undulations of current corresponding to the sound-waves of speech orto thelsignals; simultaneously bringing successive portions of a. magnetizable body under The current the inuence of said electromagnet and thereby .establishing in said body successivelyvarying magneticc'onditions; and nallysubjecting an electrolnagnet connected in a circuit, successively to the various magnetic conditions established in said body, substantially as described.

2. The method of recording and reproducing speech, signals, &c., which consists in imparting magnetic conditions successively to a magnetizable body orsurface, said conditions varying in accordance with thesound-Waves produced by said speech or signalsiand then' subjecting;r a reproducing apparatus to said magnetic conditions successively.

3. The method of storing up simials or messages represented by undulating or irregular currents, which consists in 'imparting tqvarions portions of a magnetizable body, inagnotie conditions corresponding to said undulating or irregular currents. A- y .In testimony whereetl have hereunto signed my name i'n'the presence of two wit'- DGSSES.

Witnesses: A

VALDEMAR CHQISTEISEN, NInLs CHRISTIAN BOTCHER.

VALDEMAR PoULsEN. 

